Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-08-07
Astronomy and Astrophysics
Astrophysics
12 pages, 10 figures, accepted by ApJ
Scientific paper
10.1086/592491
We demonstrate that the observationally inferred rapid onset of star formation after parental molecular clouds have assembled can be achieved by flow-driven cloud formation of atomic gas, using our previous three-dimensional numerical simulations. We post-process these simulations to approximate CO formation, which allows us to investigate the times at which CO becomes abundant relative to the onset of cloud collapse. We find that global gravity in a finite cloud has two crucial effects on cloud evolution. (a) Lateral collapse (perpendicular to the flows sweeping up the cloud) leads to rapidly increasing column densities above the accumulation from the one-dimensional flow. This in turn allows fast formation of CO, allowing the molecular cloud to ``appear'' rapidly. (b) Global gravity is required to drive the dense gas to the high pressures necessary to form solar-mass cores, in support of recent analytical models of cloud fragmentation. While the clouds still appear ``supersonically turbulent'', this turbulence is relegated to playing a secondary role, in that it is to some extent a consequence of gravitational forces.
Hartmann Lee
Heitsch Fabian
No associations
LandOfFree
Rapid Molecular Cloud and Star Formation: Mechanisms and Movies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Rapid Molecular Cloud and Star Formation: Mechanisms and Movies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rapid Molecular Cloud and Star Formation: Mechanisms and Movies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-213896